1. Field of the Invention
This invention relates to improvements in a dental handpiece designed to provide dental treatment by irradiating laser beams upon the teeth of a patient.
2. Prior Art
A dental hendpiece designed to provide dental treatment through irradiation of laser beams upon the teeth was previously proposed by the present applicant under the title of the invention "A HANDPIECE FOR DENTAL TREATMENT BY LASER BEAMS" (Japanese Utility Model Application No. 107561/1981). According to the previous application, a contra angle handpiece having a reflecting mirror therein is designed to irradiate the reflected laser beams upon the teeth through a reflection mirror internally provided at the front end of an applicator. Accordingly, the handpiece of the type described is not free from disadvantages in that microdrops of water from the vaporization of saliva on the tooth surface and cinders of India ink applied over the tooth surface before operation, attach to the mirror face gradually reducing reflection efficiency. Furthermore, there is another disadvantage that offers the possibility of the angle of radiation changing by the attached portion of the reflecting mirror becoming loosened in accordance with long term use. Not only is there a problem in connection with continued use, but also there is another disadvantage of reduction in the field of vision in dental treatment caused by the attached portion of the reflecting mirror and an increase in the number of assembling steps.